Light-emitting-diode (LED) lamps are known in the art. A LED lamp is a lamp that uses LEDs as the source of light. In such lamps, multiple diodes may be used for either increasing the output power of the lamp or for providing a white light as a single LED emits in a narrow band of wavelengths. LED lamps may be used for general lighting or even more specific lighting as the colour and the output power may be tuned.
Generally, a lamp or illumination device comprises a light source arranged to generate light and mounted on, or at least connected to, a circuit board. The light source is arranged within an encapsulating housing usually having the shape of a bulb. In addition to provide maximum light output and/or a specific colour of light, the design of an illumination device needs to take into account the evacuation of heat generated by the light source(s) and/or the electronics connected to the light source(s).
For example, American patent application US2010/0008086 discloses a white LED-based lighting device comprising a group of solid state light emitting diodes, electronics to activate the light emitting diodes and an encapsulating housing. For conducting or transferring outwardly heat generated from within the white light LED device, the encapsulating housing includes air vents and heat-sinking components.